Let me start by saying I love Amber I have never smelled Opus vi but love B9 Amber. and I'm itching for a purchase . Which one would you chose without being biased against Bond?
Opus VI is worth checking out, if only to experience it's amazing longevity. Two shots on my wrist, and my sister could smell me when I walked into the room more than 24 hours later, and after two showers.
Amouage quality as well, so that leaves you with nothing but figuring out of you love the smell of the stuff.
And having the proper bankroll, of course.
Bond No. 9 New York Amber. Both are nice. Both have great longevity. While it is true that the Amouage is a bit more of a true "amber" fragrance, there is something extremely unique about the NY Amber that I really enjoy. Opus VI is a nicely blended amber/incense fragrance that is pure quality, but if forced to pick just one of the two, I would lean toward the sillage beast that is New York Amber.